Field
Embodiments disclosed herein generally relate to magnetic recording systems with improved reliability having a spindle motor and, more particularly, to an optimized lubricant for bearings within the spindle motor.
Description of the Related Art
With the advent of interface voltage control (IVC), it is more important than ever to provide a fluid dynamic bearing spindle motor in a magnetic recording system with stable electrical properties. In particular, the fluid bearing oil, or lubricant, is the main contributor to variation in the interface voltage with respect to time and temperature. The main reason for the changes in electrical properties of the fluid bearing motor lubricant with respect to time is that the antioxidant is also a charge control agent. As the antioxidant scavenges free radicals, it undergoes chemical changes that alter the charge transfer properties. Thus, the voltage across the fluid bearing drifts, which may lead to slider disk interaction gradually over time.
Therefore, there is a need for a stable charge control agent that is resistant to free radical oxidation.